In this study,an X-band standing-wave biperiodic linear accelerator was developed for medical radiotherapy that can accel-erate electrons to 9 MeV using a 2.4-MW klystron.The structure works atπ/2 mode and adopts mag...In this study,an X-band standing-wave biperiodic linear accelerator was developed for medical radiotherapy that can accel-erate electrons to 9 MeV using a 2.4-MW klystron.The structure works atπ/2 mode and adopts magnetic coupling between cavities,generating the appropriate adjacent mode separation of 10 MHz.The accelerator is less than 600-mm long and constitutes four bunching cells and 29 normal cells.Geometry optimizations,full-scale radiofrequency(RF)simulations,and beam dynamics calculations were performed.The accelerator was fabricated and examined using a low-power RF test.The cold test results showed a good agreement with the simulation and actual measurement results.In the high-power RF test,the output beam current,energy spectrum,capture ratio,and spot size at the accelerator exit were measured.With the input power of 2.4 MW,the pulse current was 100 mA,and the output spot root-mean-square radius was approximately 0.5 mm.The output kinetic energy was 9.04 MeV with the spectral FWHM of 3.5%,demonstrating the good performance of this accelerator.展开更多
Assisted by the bead pull technique,nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure.The method is capable of making non-touching amplitude and phase me...Assisted by the bead pull technique,nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure.The method is capable of making non-touching amplitude and phase measurements,real time mismatch feedback and field tuning.Some key considerations of the measurement system and of a C-band traveling-wave structure are discussed,and the bead pull measurement and the tuning of the C-band traveling-wave linac accelerating structure are presented at last.展开更多
In this paper, we present the RF simulation, the fabrication and the normal RF test of a six-cell copper model cross bar H mode （CH） cavity. The CH cavity was researched and developed at the Institute of Modern Phys...In this paper, we present the RF simulation, the fabrication and the normal RF test of a six-cell copper model cross bar H mode （CH） cavity. The CH cavity was researched and developed at the Institute of Modern Physics for Injector II of the superconducting linac of the accelerator driven system of China, operating at a frequency 162.5 MHz, β=0.065. The deep drawing and electron beam welding were employed to fabricate this cavity, which would be used to develop the superconducting CH cavity in the future. The results of the normal RF test agree with the simulation of the electromagnetic properties, such as the electric field distribution on the cavity axis, frequency and Q factor.展开更多
基金the Key R&D Project of the Ministry of Science and Technology of China(No.2022YFC2402300).
文摘In this study,an X-band standing-wave biperiodic linear accelerator was developed for medical radiotherapy that can accel-erate electrons to 9 MeV using a 2.4-MW klystron.The structure works atπ/2 mode and adopts magnetic coupling between cavities,generating the appropriate adjacent mode separation of 10 MHz.The accelerator is less than 600-mm long and constitutes four bunching cells and 29 normal cells.Geometry optimizations,full-scale radiofrequency(RF)simulations,and beam dynamics calculations were performed.The accelerator was fabricated and examined using a low-power RF test.The cold test results showed a good agreement with the simulation and actual measurement results.In the high-power RF test,the output beam current,energy spectrum,capture ratio,and spot size at the accelerator exit were measured.With the input power of 2.4 MW,the pulse current was 100 mA,and the output spot root-mean-square radius was approximately 0.5 mm.The output kinetic energy was 9.04 MeV with the spectral FWHM of 3.5%,demonstrating the good performance of this accelerator.
基金supported by Program of Shanghai Subject Chief Scientist and Natural Science Foundation of China (key program) (Grant No. 08XD1405400)
文摘Assisted by the bead pull technique,nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure.The method is capable of making non-touching amplitude and phase measurements,real time mismatch feedback and field tuning.Some key considerations of the measurement system and of a C-band traveling-wave structure are discussed,and the bead pull measurement and the tuning of the C-band traveling-wave linac accelerating structure are presented at last.
基金Supported by National Natural Science Foundation of China(91026001)
文摘In this paper, we present the RF simulation, the fabrication and the normal RF test of a six-cell copper model cross bar H mode （CH） cavity. The CH cavity was researched and developed at the Institute of Modern Physics for Injector II of the superconducting linac of the accelerator driven system of China, operating at a frequency 162.5 MHz, β=0.065. The deep drawing and electron beam welding were employed to fabricate this cavity, which would be used to develop the superconducting CH cavity in the future. The results of the normal RF test agree with the simulation of the electromagnetic properties, such as the electric field distribution on the cavity axis, frequency and Q factor.
